Hi I have Sanwa Airtronics Mx-3 75mhz that currently has channel 71 in it. I wanted to use the same remote for another car so I purchased Futaba R303 synthesizer receiver. After i dialed in channel 71 there is no response. I thought futaba and airtronics equipment isnt compatable so I tried 75mhz Futaba R123F RX and put in the channel 71 crystals and it certainly works. Is there any explanation what the futaba synthesizer receiver doesnt work with the MX3 transmitter?

I know the synthesizer does work as i tested it with another 75mhz futaba mj transmitter with channel 66. The unusual thing here is that when I put channel 66 crystals in the Mx3 nothing works

Any info would be great! Thanks

I've always been told there's a phase shift difference between Futaba and Hitec (negative shift) and JR, Airtronics, KO (positive shift) and this difference only exists for 75MHz FM. AM or 27MHz FM they would work.

They don't work together as you've already found out.

I would think that in your case you might have better luck with a Novak XXtra sythensized receiver. Being that its a aftermarket receiver they probably worked through those issues. I can't say for certain though.

Steve

I know the novak XXtra synth rx works with the futaba gear since I'm running a few of the novak XXtras with my 3PK and 3PJS radios. Can't say that it'll work with your Airtronics. My guess is that it wouldn't due to the phase shift difference.

I don't know if Novak did something to resolve that issue.